This invention relates to windshield wipers, and more particularly, to an improved windshield wiper assembly capable of removing dried insect debris from a windshield.
All automobiles and trucks are equipped with windshields or wind screens which require periodic cleaning while the vehicle is under way. Therefore, all such vehicles are likewise equipped with windshield wipers which are adapted to move in a back-and-forth or to-and-fro motion in order to sweep across a major portion of the windshield and remove water therefrom. Conventional windshield wipers are adapted to function in a "squeegee" manner--that is, the rubber windshield wiper blades scrape across the windshield surface and remove water therefrom. Most automobiles and trucks produced after the early 1970's are also provided with windshield washer fluid delivery systems, wherein cleaning fluid may be delivered to the windshield to aid the windshield wipers in removing dirt or dust therefrom. Windshield wipers have been designed so that they bear against the windshield with a moderate amount of force--enough to sweep the surface of the windshield clean, but generally not enough to effect any scrubbing action by the wiper blade, since the purpose of the wiper blade is to remove water.
The problem that has existed for some time is that when flying or airborne insects impact against the windshield of a rapidly moving automobile or truck, the body fluids of the insect, and to some degree the exterior body parts, adhere to the windshield and are quickly dried thereon. The resulting windshield smear is, for the most part, impossible to remove by the squeegee action of a conventional windshield wiper blade, even when assisted with windshield washing fluid. A number of modifications to conventional windshield wipers have been proposed in the past to solve this problem, most of which deal with the problem by increasing the amount of pressure applied to the windshield by the windshield wiper. For instance, U.S. Pat. No. 3,089,175 proposes to remove the conventional linkage assembly between the removable wiper blade and the blade carrier, and replace it with a plurality of magnets spaced along the length of the wiper blade in order to exert uniform pressure against the windshield to be cleaned. U.S. Pat. No. 3,058,141 proposes to increase the pressure between the wiper blade and the windshield as engine speed increases, so as to reduce the problem of wind-lift of the wiper blades. Compressed air is used in order to apply greater pressure to the windshield, and a light spring is used to maintain sufficient contact between the wiper blade and the windshield even when the wiper motor is inoperative.
Likewise, U.S. Pat. No. 3,685,086 discloses an attachment for windshield wipers which clamps onto a wiper arm and comprises a plurality of transverse wind-catching ribs progressively increasing in height from a narrow end to a wide end of the unit. The ribs utilize the force of wind impacting against the windshield when the car is moving to increase the pressure of the windshield wiper against the windshield.
Various foreign patents have been issued directed toward the same result, including Japanese Pat. No. 58-9365 (A) and West German Offenlegungsschrifts Nos. 1,505,430 and 1,938,618.
Finally, U.S. Pat. No. 3,939,524 discloses a wiper blade assembly wherein a wiper blade is provided with a pair of squeegee lips in an inverted U-shape, with brush material disposed therebetween. A windshield washer fluid cavity is located above the brush material in order to distribute the fluid along the entire length of the wiper blade. This is an attempt to deal with the problem noted above, wherein the brushes assist the wiper blade in removing debris from the windshield.
While all of these devices may provide some benefit over that of a conventional windshield wiper/washer, the problem of removing the dried bug debris still remains--none of these devices provides the proper "scrubbing" action necessary to remove such material. Therefore, it is an object of the present invention to provide a windshield wiper assembly capable of removing dried bug debris through the proper combination of scrubbing, fluid application and squeegee action.